i just bought a brand new pc intel core duo 1.60ghz with 1g of ram.everything looks fine till the day i uninstall the norton antivirus which just a trial version.my video card is nvidia geforce 8500(512mb).My problem is after i uninstall the norton anti virus.Everytime i start my computer its stuck and i need to press f1 regularly so i can use my computer.pls help...